1. Field of the Invention
The present invention relates to a device for processing road data or intersection data and, more specifically, to a navigation device in which a route along which a moving body will travel is identified based upon map data, and the route that is identified is displayed to the operator. In particular, the invention relates to a navigation system which learns the route of travel.
2. Description of the Related Art
A conventional navigation device has been disclosed in, for example, Japanese Unexamined Patent Publication (Kokai) No. 194473/1986. According to this navigation device, a map of a desired area is displayed on a display unit based upon the stored map data. Conditions for identifying the facilities are shown on the screen of the display unit, the conditions for identification are selected step by step, and a facility desired by the user is set as a destination.
The position of the thus set facility is indicated by a discrimination mark on the map screen. Based on the map data, furthermore, the navigation device searches a route from the present position to the facility that is set and displays the route on the screen. While the moving body is traveling along the route, the user is informed of various necessary data (road into which the moving body should enter, etc.) by voice or the like means.
This navigation device searches the routes and selects a route based upon cost of the roads or intersections memorized previously. However, a route which a driver wishes to travel sometimes does not agree with the route which the navigation device selects.
For example, the driver may wish to travel a road which the driver usually takes as the route, but the navigation device may select a different route. And the navigation device sometimes selects a route which the driver does not wish to travel. Further even if the vehicle has earlier taken a short cut to a destination through a back road, the navigation device sometimes selects a roundabout guide through a main street.